Adding device.



the slides 6 to the lift of the figure 5 in the thousands-column and pulls down the slide as far as the point will go or until it strikes the bottom of the slot 12. He next pulls down the slide in the hundreds-column. by in-- serting the pencil to the left of H7 in said column. He next inserts the pencil to the left of 3 in the column of tens, drawing it down, as before, and then inserts the pencil at 6 in the column of units and draws it down. He then laces the point of the pencil o posite the in the lower halffof the hun eds-column and pushes it upas far as the pencil will permit him to go and then immediately pulls down l in the next slide to the left, or the thousands-column. He then places the pencil at 7 in the lower half oi the column of tens, pushes it up as far as the pencil will permit, and pulls down l vin the next column to the left or the hundreds-column. He then pushes up the 4 in the units-column in the same manner and pulls down l in the tens-column. He then pulls down the 3 in the upper half of the thousands column and pushes up the 7 in the hundreds-column, and as the slide of the thousands-column is down at9 pushes this slide back to 0 and pulls down .1 in the tens-of-thousands column. He then pulls down the 4 in the tcnscolumn and the 5 in the column. of umts. He then pulls down the 3 in the tens-column, pushes up the 9 in the column of units, and pulls down l in the tens-column. The answer, 16,694, is read in the apertures 1 l. The rule to be followed in calculating is that every 'time a slide is pushed up immediately pull down i in the next higher column that is, the next column on the lette-or, if this slide is down at 9, push it back to 0 and pull down l. in' the second column to the lett, and so on.

I have provided a very simple form oi an adding device, which is composed of three thin s ieets of metal or other suitable material so held together as to form a device oit singes very little thickness, while at the same time by having the slide of substantially half the length of the guide-slots I am enabled to very materially shorten the length of the plate so that it is of a size which is conveniently handled or carried about in the pocket, if desired.

lt is a very simple matter to remove the fastenings or clips which secure the plates together in order t0 get at the working parts in tending across the same and two series oi slots, and bearing numbers adjacent to each of said slots, and a series ci slides bearing numbers mounted in said guides opposite said o enings and provided with means accessib e throuh both series of slots lor the engagement o moving means, the numbers on said slides and those adjacent both series of slots all running consecutively in the same direction.

2. An adding device comprising a frame having a series of guides therein, slides substantially half the length of said guides car-- rying numbers adapted to be moved from one end to the other of said guides, and a front plate having two sets of slots formed therein at its opposite ends and having openings intermediate of said slots and numbers ruiming parallel with said slots, the numbers on the slides and those adjacent the two sets of slots running consecutively in the same di rection.

in testimony whereof l, the said EDWARD C. DILWORTH, have hereunto set my hand.

EDNARD C. DlljZ/@RTH- litnesses:

ROBERT C. Torrnn, Roer. D., Terran. 

